Art of making phosphorescent colors.



UNITED STATES PATENT ()FFICE.

ROBERT F. LARGER, 01 SAN FRANCISCO, CALIFORNIA.

ART MAKING PHOSPHORESCEN'I COLORS.

1,244,058. No Drawing.

To all whom it may concern:

Be it known that I, ROBERT F. LANGER,

a citizen of the United States, and resident ments in Art of MakingPhosphorescent Colors, of which the following is a specification.

The invention relates to the method of preparing and compoundingsubstances which will phosphoresce or give off light after beingstimulated by exposure to a light source, and other substances whichwhen used in conjunction with the phosphorescent substances, will causeemission of light of various colors. The principal object of theinvention is to provide such substances which when used incombinationwith one another, will emit phosphorescent light of anydesired color after stimulation, and which will continue to do so for aconsiderable period after having been removed from the stimulatin lightsource.

A further 0 ject is to rovide phosphorescent compositions which can beused in the nature of a paint or coating for various objects to renderthem visible in the dark and in any desired luminous color orcombination of colors.

This would be found useful, for example, in the case of railroadcrossing, warning and other signals, motor car signals, auto-roadbulletins, street signs, house numbers, fire alarm boxes, night bellsigns for doctors, watchmen and the like, To-let, For sale, etc., signs,for marking bottles and packages containing dangerous or poisonoussubstances, advertising and novelty devices, Christmas-tree ornaments,names of firms and buildings, hotels, hos itals and stations, to showthe location of ells, electric light switches, match containers, etc.,for Danger, Exit, etc., si s, for illuminating the interior of wardroes, etc. V

The composition may also be used for decorative purposes; for example,pictures, designs, coats-of-arms and the like may be painted or printedwith the various compositions, so that the resultant phosphorescentlight will cause the picture or design to appear luminous in the dark inits appropriate colors.

Specification of Letters latent.

' The composition used for producing this vari-colored phosphorescenteffect is composed of the substances as specified below and prepared andtreated in the manner Patented Oct. 23, 1917. Application and March 15,1910. Serial 1%. asses.

sition, is that primarily used for causing phosphorescence and iscomposed of lithium carbonate, sulfur, barium carbonate, d1stilled waterand ethyl alcohol. This substance by itself will produce phosphorescentlight yellow in color. When coated however, with any of the compositionsnamed below, the wave length of the li ht emitted will be altered andthe resulting ight be of the corresponding color.

These secondary compositions are composed as follows No. 2Greencomposition: Thorium mtrate, strontium thiosulfate, bismuth nitrate,

potassium sulfate, starch, sulfur, ethyl alcohol and distilled water.

No. 3-Yellow composition: Manganese sulfite, strontium carbonate, sodiumchlorid, sulfur, anhydrous sodium carbonate and ethyl alcohol.

No. 4-Red com osition: Rubidium carbonate, lithium car onate, bariumcarbonate, sulfur, distilled water and ethyl alcohol.

No. 5-Light blue composition: Calcium oxid, starch, calcium sulfate,sulfur, sodium sulfate, bismuth nitrate solution (in alcohol), unraniumnitrate solution, distilled water and ethyl alcohol.

No. 6-Blue composition: This may be composed of ammonia alum, cobaltsulfate, distilled water, ethyl alcohol and (a) zinc sulfate, or (b)lead sulfate.

No. 7Violet composition: Sodium sulfate, calcium sulfate, calcium oxidstarch, sulfur and a solution of bismuth mtrate in absolute alcohol.

In preparing any of these com ositions the dry ingredients, inpulverized orm, are first thoroughly mixed. Solutions are then prepared0 bismuth nitrate and uranium nitrate in approximately the proportion of0.5 oz. of nitrate to 100 c. c. absolute alcohol. Sufiicient of one orthe other of these solutions, or of water or alcohol, or all as the casemay be, is then added to the dry inthoroughly mixed. Small quantities ofthallium ts may also be added, which will materially increase theluminescent effeet.

,1 As an example of such a mixture, the No.

These substances are pulverized and thoroughly mixed, after which 1 c.c. of bismuth nitrate solution, prepared as described, is added andstirred into the mixture. n The mixture thus prepared is next heated inan oven to 1 F. or higher and thoroughly baked and desiccated, afterwhich it is ground in any suitable one of the heavier mineral oils, suchas parafiin oil, petrolatum or. the like. To this is added a'suitabledrier and the mixture applied where desired as a paint, or it may alsobe used for printing the pattern or design required.

When an object or surface is to be rendered phosphorescent, the No. 1 oryellow phosphorescent composition is first applied by painting orprinting and after this has become dry, any suitable one of the othercompositions is applied over the first to produce luminescence of thedesired color.

In order to render the paint proof against this paint, and which areexposed to' day ally be applied. Surfaces treated in this way andexposedlight, will continue to be visible in any de-..

color or combination of colors ar Having thus described my invention andthe manner of its preparation and use, what 1 claim as new and desire tosecure by Letters Patent is The art of producing phosphorescent colorswhich consists of first coating the surface with a basic compositioncomprising lithium carbonate, sulfur barium carbonate, water and alcoholand addin a composition conslstlng of manganese s w strontium carbonate,sodium chlorid, sulfur, anhydrous sodium carbonate and ethyl alcoholthereb altering the influence of light rays accor 111% the nature of thesecond composition. igned at San Francisco, in the county of SanFrancisco and State of California this QQth'day-of February, A. D. 1916.

ROBERT F; LANGER. Witnesses:

BENJ. WM. s, Am'nnn E. DAY.

